Add Super 32X Emulation

[CRTRevivalDreamer]

Currently higan doesn't have a SEGA Super 32X emulation core,
and I'd like to have it someday in the future.

[near-san]

I can tell you with certainty that it cannot be done at 60fps with an interpreter. At least not in the design spirit of higan. 2x23MHz (and very nearly 23 MIPS at that) is just too demanding with cooperative threading synchronization in addition to all the other parts of the Mega Drive and potentially Mega CD added in.

I've added this to ares, but dynamic recompilers go against the design goals of higan's cycle-accuracy. Recompilers aren't even opcode-acurrate, but block-accurate. The 32X VDP also has to run scanline-based instead of pixel-based.

[CRTRevivalDreamer]

Maybe we need computers with processors faster than 5 GHz and/or with at least 8 cores in order to do Super 32X emulation at 60 fps with an interpreter...